== Panel (a) UHPLC-UV chromatograms of total extract (TE), DESIGNER extract (MultiT-DE, in blue), andK-targeted subtracted metabolites (in green) generated in the pilot study. separation steps were used to purify each of the four compounds, and four DESIGNER extracts with varying depletions were prepared. The DESIGNER approach innovates the characterization of chemically complex extracts through integration of enabling technologies such as countercurrent separation,K-by-bioactivity, the residual complexity concepts, as well as quantitative analysis by1H NMR, LC-MS, and HiFSA-based NMR fingerprinting. Botanical dietary supplements, KR-33493 and other natural health products in general, are highly complex chemical entities. Even well-authenticated products such as single herbal extracts originate from complex chemicalbiological matrices that contain (many) thousands of metabolites. These metabolomes are formed by interactive biosynthetic pathways from a combination of common building blocks that bring about a vast array of chemodiversity. The inherent complexity of the metabolome is the origin of residual complexity (RC),1a phenomenon encountered ubiquitously in natural product research. The residual complexity concept explains many of the persistent challenges associated with natural product drug discovery as well as projects directed at the identification of (multiple) biological activities and active lead compounds. KR-33493 One example of a well-studied botanical, which has evaded the reductionist models of scientific investigations, is preparations derived from hops (Humulus lupulusL., Cannabaceae). As detailed below, the plethora of knownH. lupulusconstituents, including those more recently discovered, still does not provide a persuasive explanation of numerous, traditionally well-founded beneficial uses ofH. lupulusfor human health.2,3 The majority of studies on botanicals and complex natural (health) products take a reductionist approach and are directed at finding single or a few actives from the metabolome. More importantly, focusing on a single or very few of their constituents may not necessarily unravel relevant biology. In addition, this approach bears a similar risk of failing to explain the observed biological activity, both qualitatively and quantitatively, as does the approach of bioassay-guided fractionation. One highly influential concept in modern biomedical research is the targeted deletion of specific genes and the generation of knockout strains of organisms. This concept is widely applied to microbes (e.g., knockoutEscherichia coli) and animals (e.g., knockout mice). Considering the similarities in the complexity of genomes and metabolomes, the process of knocking out single entity can be an important concept in studying the overwhelming complexity of both genes and metabolomes, respectively. The approach of targeted removal (knockout) of a single, or several selected,chemicalentities represents a compelling alternative to studying metabolomic natural (health) products. However, while the complete and selective removal of a single entity may be desirable, doing so with very high specificity is rather KR-33493 challenging and/or quite laborious (see knockout concept below). The present work introduces the concept ofDepletion andEnrichment ofSelectIngredientsGeneratingNormalizedExtractResources (DESIGNER) as a novel approach to exploring the biology of complex extracts. The concept integrates advanced countercurrent separation (CS; includes countercurrent chromatography [CCC] and centrifugal partition chromatography [CPC]) methodology with metabolomic analysis by LC-MS, UHPLC-UV, and quantitative1H NMR (qHNMR) for the targeted design of selectively prepared extracts. This process yields DESIGNER materials that are derived from otherwise unaltered metabolomic mixtures such as natural product extracts (Figure1). The concept of DESIGNER extracts utilizes the flexibility of possible adjustments of chromatographic selectivity, polarity, and orthogonality and can thus target single and multiple metabolites, producing single and multiple knockout, knock-down, and knock-in extracts. The present study elaborates the DESIGNER concept for single and multiple modifications of an extract of hops (H. lupulus) developed for in vivo studies.2Hops consist of the dried strobili ofHumulus lupulus, and they have been shown to contain a plethora of phytochemical constituents such as essential oil, di-, and triprenylated phloroglucinol derivatives, chalcones, and other prenylated flavonoids, such as isoxanthohumol (1), 8-prenylnaringenin (2), Rabbit Polyclonal to AQP3 6-prenylnaringenin (3), and xanthohumol (4). Hops have been associated with a variety of biological activities,27and the prenylphenols14(Chart1) are widely considered bioactive marker compounds (S1,Supporting Information, provides an overview of the activities). Moreover, as materials that contain complex patterns of both chalcones and flavanones, hops extracts represent known cases.